Polymethine dyestttees



Patented June 21, 1932 UNITE STATES PATENT FFKIEA I OT'I'MAR WAHlL, OF LEVERKUSEN-ON-THE-RI-IINE, GERMANY, ASSIGNOR TO GENERAL if ANILINIE WORKS, INC., OF NEW YORK, N. Y., A. CORPORATION OF DELAWARE IPOLYME'I'HINE DYESTUFFS No Drawing. Application filed June 24, 1929, Serial No. 373,475, and in GermanyiuneEZS, 1928, f

The present'invention relates to a process of preparing polymethine dyestuffs and t the new products obtainable thereby, more particularly it relates to dyestuffs of the probable general formula reaction is favorably performed in a solvent, such as a tertiaryamine, for example pyridine or dimethyl aniline, by heating the tween 50 C. and the boiling point of the mixture. It is, however, to be understood whereinthe, Rs stand for alkyl groups, w

' stands for amonovalent radical of a strong inorganic acid, such as Cl, HSO N0 My 'new dyestuffs are obtainable by causing a pyridinium salt, the nitrogen atom of wh ch is labile, such as the dinitrophenyl pyridinium chloride, or a pyridinium cyano-halogenide to react upon about the double molecular" quantity of a 1.3.3-trialkyl-2-methylene-indoline of the general formula the Rs meaning alkyl groups, 00 a monovalent radical of a strong inorganic acid.

The process can be carried out by melting together the two components for a prolonged time, say for several hours; but the that the reaction'alsotakes place at lower temperatures, but it only proceeds -vry slowly. The reaction proceeds according to the following scheme 5 a i a l R g wherein 3 stands for thedinitrophenyl' resi- .components therein for several hoursbe due or the cyano group, thelts stand for-l alkyl groups, and 0a representsamonovalent radical of a strong inorganic acid. The same polymethine dyestuffs are obtainablebyfirst decomposing the above mentioned pyridinium salts with labile nitrogenatom, with a primary or secondary aromatic amine ,in-the same manner, favourably'in an excess ofgthe baseas solvent, at elevated temperatures, say between 50 C. and the boiling point of the mixture (compare W. 'Konig, J ournal/fiir Zincke, Annalen der Chemie, vol., 330, page 7361, seq.), isolating the dyestuff, formed; and

decomposing it with about the doublesequi- .molecular quantity of a='1.3.-3-trialkyl-'2- methylene-indoline, or a 7 salt thereofizunder V the same conditions asin :the first stage,

favourably in a tertiary amine atTelevated praktische Chemie, vol. 69, page 105, and

temperature, above described; Th'e whole" Ail) process of this latter method may be repreinto hot water and filtered while hot. On

sented by the following scheme the Rs meaning alkyl groups, y thedinitrophenyl residue or the cyano group, R an aromatic nucleus, R hydrogen oralkyl, and a: a monovalent radical of a strong inorganic acid. The new dyestuffs are generally dark,

The following examples will serve to illustrate the invention, but without limiting it thereto. 1

Example 1.-1' mol of dinitrophenyl-pyridinium chloride and 2 mols of 1.3.3-trimethyl-2smethyleneindoline and dissolved in pyridine and heated to 100 C. until the quantity of the blue dyestuff formed does not increase. Then the mixture is poured, into hot water, filtered olf from resinous constituents, and the dyestuff is salted out from the solution. Its hydrochloric acid salt is easily soluble in hot water and separates on cooling or salting out with NaCl in the form of crystals, having a metallic lustein.

Dyed accordingeto the dyeing methods for basic 'dyestulfs, it produces on the fiber (tanned cotton and silk and the like) a very clear greenish blue shade. The dyestuff has the following structural formula OH; I V orn .01 V EmampZe 2.3parts by weight of the yellow -dyestufi',obtainable from 1 mol of dinitrophenyl pyridinium chloride and 2 mols of methylaniline, of the following formula:

1 CH; CH3 p are heated at C. for-a few hours with a mixture of 1.3.3-trimethyl-2-methylene-indoline and the acetate of this 'base obtained until the yellow dyestuff has'disappeared. .At a higher temperature the reaction pro ceedsmore quickly. The mixture is poured cooling the blue dyestufi crystallizes. The

dyestufi? is identical with that obtained according to Example 1. p v

'I claim: 7

1.v The process which comprises heating a compound of the probable general formula: metallic powders, ,difficultly'soluble in cold water, dyeing blue to green shades.

on, C1 on.

"with aboutthe double equimolecular quantity of .a 1.3.3-trialkyl-2 methylene-indoline.

3. The processgwhich comprises heating a compound of theprobable formula:

CH3 01 H with about the double equimolecular quantity of the hydrochloric acid salt of 1.3.3- trimetl1yl-2-methylene indoline.

4. The process which comprises heating a compound of the probable general formula R2 R2 N-'oH=oH-oH=oH-on=N wherein R 'stan'ds for hydrogen or an alkyl group, R stands for a radical of the benzene series, and m stands for a monovalent radical of a strong inorganic acid, with about the double equimolecularquantity of a 1.3.3-trialkyl-2-methylene "indoline in a tertiary amine asa solvent, between about 50 C. and the boiling point of the reaction mixture.

5. The process which comprises heating a compound of the probable formula:

with about the double equimolecular quantity of 1.3.3-trimethyl-2-methylene indoline in a tertiary amine as a solvent, between about 50 C. and the boiling point of the reaction mixture.

7. As new products dyestufis of the probable general formula wherein the Rs stand for alkyl groups, a; stands for a monovalent radical of a strong inorganic acid, said dyestuffs being generally dark metallic lustrous powders, difficultly soluble in cold water, dyeing blue to green shades.

8. As a new product the dyestufi' of the H; CH3

said dyestuff being a dark metallic lustrous powder and dyelng clear greenish blue shades.

In testimony whereof I have hereunto set my hand.

OTTMAR WAHL. [L. s.] 

